A technology of making a radio frequency (RF) circuit in a wireless communication field using a micro-wave band or a millimeter wave band from a complementary metal oxide semiconductor (CMOS) has been advanced, and studies about miniaturization and low power consumption for commercialization of the RF circuit have been intended.
The intensity of a transmission wave, that is, the power of the transmission signals is defined in specified low power wireless communications using the millimeter-wave band, for example, a 60 GHz band. In a high-frequency region (for example, a millimeter wave band), the threshold voltage of a transistor constituting an integrated circuit (IC) chip varies depending on a process variation, a temperature fluctuation, or a power voltage fluctuation, such that high frequency characteristics greatly vary. Accordingly, since the power of a transmission signal changes in some cases, the power control of the transmission signal is needed. In other words, it is necessary to control the transmission power to be a constant value by measuring the power of the transmission signal.
For example, Patent Literature 1 and Patent Literature 2 are known as the related arts about a wireless communication apparatus that controls the power of the transmission signal to be constant. A wireless transmitter disclosed in Patent Literature 1 changes a reference voltage to be applied to a digital analog converter (DAC), according to a measurement result of the power of a high-frequency signal, and thus changes a power level of a base-band signal so as to control the level of transmission power of the high-frequency signal to be constant.
In addition, an RF power amplifier disclosed in Patent Literature 2 controls the transmission power level of the high-frequency signal to be constant by applying an automatic power control voltage that is output by an error amplifier connected to a negative feedback circuit and an attenuator, to an RF power amplifier, according to a measurement result of the power of a high-frequency signal. In addition, the operations of the respective apparatuses of Patent Literature 1 and Patent Literature 2 will be described later with reference to FIG. 14 and FIG. 15.